1. Field
Embodiments relate to a light emitting device.
2. Background
Light emitting devices, such as light emitting diodes or laser diodes using group III-V or II-VI compound semiconductor materials, generate light of various colors, such as red, green, blue, and ultraviolet light, due to development of thin film growth techniques and device materials, and generate white light having high efficiency using fluorescent materials or through color mixing. Further, light emitting devices exhibit low power consumption, semipermanent lifespan, fast response time, safety, and eco-friendliness, as compared to conventional light sources, such as fluorescent lamps and incandescent lamps.
Therefore, light emitting devices are increasingly applied to transmission modules of optical communication units, light emitting diode backlights substituting for cold cathode fluorescent lamps (CCFLs) constituting backlights of liquid crystal display (LCD) devices, lighting apparatuses using white light emitting diodes substituting for fluorescent lamps or incandescent lamps, head lights for vehicles, and traffic lights.
In case of a horizontal type light emitting device, a light emitting structure including an n-GaN layer, an active layer, and a p-GaN layer is generally stacked on a sapphire substrate. Due to characteristics of the horizontal type light emitting device, an n-electrode and a p-electrode are horizontally formed and may cause high current spreading resistance. Such a problem occurs even in a light emitting device in which plural light emitting cells are connected in series or in parallel. Therefore, in order to enhance current spreading, the positions of the n-electrode and the p-electrode need to be optimized.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.